Such printed circuit boards with a precision resistor as part of a measuring device for the current flowing between the connection points are known from prior art. The precision resistor, which is composed, for example, of solid electron-beam-welded composite made from copper and resistance alloys, is as a surface-mount device (SMD) soldered onto an existing circuit or connected via bonding wires. By measuring the voltage between connection points and due to the known electric resistance value, which generally varies only slightly due to the extremely low temperature coefficient of the materials used in the relevant temperature range of 20 to 60° C., the current flowing between the connection points can be determined with high accuracy.
The manufacture of these printed circuit boards is comparatively complex and expensive. Connecting the precision resistor at the connection points is often also susceptible to vibrations which can reduce the service life of the printed circuit board. In addition, the trend in many technical applications (for example, automotive, smartphone, etc.) is toward minimizing the size (“downsizing”) which limits in particular the installation space of the electrical components, such as printed circuit boards, used for this purpose.
The invention is therefore based on the object to inexpensively produce a printed circuit board of the type mentioned above such that the printed circuit board has a reduced installation space while having a preferably long service life.